decode.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Decode Unicode</title>
  <style>
    textarea {
      width: 45vw;
      height: 90vh;
    }
  </style>
</head>
<body>
  <textarea name="" id="input" cols="30" rows="10"></textarea>
  <textarea name="" id="output" cols="30" rows="10"></textarea>
  <div>
    <button id="decode">转码</button>
  </div>
  <script>
    var input = document.getElementById('input');
    var output = document.getElementById('output');
    var decode = document.getElementById('decode');

    decode.onclick = function() {
      try {
        var value = input.value;
        output.value = JSON.stringify(JSON.parse(value), null, 2);
      } catch(err) {
        alert(err.message);
      }
    }
  </script>
</body>
</html>